The present invention relates to an ink recording apparatus having a recording head which has an integral ink container for supplying ink to the recording head, and more particularly to reduction of the size of the entire apparatus or parts thereof. The present invention is directed to an ink recording apparatus usable for a printer, copying machine, wordprocessor, personal computer, facsimile or a combination of two or more of them.
Conventional ink supply mechanisms for an ink recording apparatus are classified into the following three groups. In the first type, the recording head is used for a long term (permanent type recording head), and the ink is supplied to an ink supply passage of the recording head from a large size ink cartridge. In the second type, the recording head has an integral ink container, and the integral recording head and the container are mountable as a whole. In the third type, the recording head has an integral ink container, and the ink can be replenished at a predetermined position, or the ink can be manually replenished by the operator.
In one of practical driving means for an ink jet recording head, an electrothermal transducer or a photo-thermal transducer applies thermal energy to the ink so as to cause film boiling of the ink to create a bubble, thus ejecting a droplet of the ink by the volume expansion of the bubble. In another practical ink jet recording head driving means, an electromechanical transducer is used to eject the ink.
In such an apparatus, the size of the printer is reduced, but the reduction is not enough to permit a built-in printer to be incorporated in a compound apparatus.
The reasons for this inability are as follows. When the printer is built in a compound or complex apparatus, the position of the printer is limited. In order to reduce the size of apparatus, size reduction and compound mechanism are further required to accommodate the printer in a limited space. The problems are analyzed by the inventors as follows.
(1) In a conventional recording apparatus in which a head cartridge is detachably mountable, the positioning between the recording head and the carriage, the positioning among the carriage, the flexible cable pads and the flexible cable, and the positioning between the head contact portion and the recording head, are independently set. In other words, the positioning actions are carried out at plural positions, so that the positioning between the elements which are not directly indexed is inaccurate. For example, even if the recording head is correctly positioned, the electric contacts are not accurately positioned. The positioning portions at different locations produce a complicated mechanism, and therefore, the size and the cost of the apparatus increase.
(2) In many machines such as a printer, scanner or the like, a flexible cable is widely used for transmission of signals and/or electric power between a movable side such as a recording head, sensor or the like and a fixed side such as the main assembly. The reduction of the size of these machines is highly desirable. On the basis of the number of cable patterns and current capacity required by the apparatus, the thickness and width of the pattern of the flexible cable, that is, the thickness and the width of the flexible cable, are determined. On the basis of the material and thickness of the flexible cable, the height required for folding the flexible cable so as to assure the durability of the machine, is determined, and therefore, the space required by the flexible cable is large. Heretofore, as shown in FIGS. 45A and 45B the flexible cable is divided into plural parts which are overlaid, by which the width required by the flexible cable arrangement is reduced.
However, with this method, the rigidity of the overall flexible cable increases because of the influence of the flexible cables at the bent portion, with the result of reduction of the durability of the flexible cables, and therefore, the bending height xe2x80x9chxe2x80x9d is required to be larger than when the overlaying structure is not used. Therefore, the space required by the flexible cable is not reduced. As shown in FIG. 45B, the inside flexible cable is locally bent at 1100xe2x80x2v, with the result of the reduction of the durability of the flexible cable against the bending.
In a conventional friction separation type sheet feeding apparatus, as used in an original feeding device of a facsimile machine, a separating roller exerts a constant pressure. Therefore, after the sheet is discharged to the main apparatus, the main apparatus is required to pull the recording sheet out of the sheet feeding device with very strong force.
This requires the entire apparatus to be rigid, and prevents the reduction of the size and the power consumption. In addition, the large load required for sheet feeding results in inaccurate sheet feeding.
(4) In a conventional friction separation sheet feeding machine, as used in the recording sheet feeding mechanism of a copying machine, the sheet is fed to the friction separation portion by inclining the recording sheet toward the friction separation portion to permit feeding by the weight of the recording sheet.
(5) In a conventional friction separation type sheet feeding device, as used in an original feeding mechanism in a facsimile machine, a separation roller is located at a center of the sheet, and guiding members are provided at both sides to align the center of the recording sheet in the center of the separation roller based on the width of the sheet. In the conventional device, the guides are required at both sides, which prevents the reduction of the size. When the recording sheet is aligned at one lateral side not at the center, the center of the separation roller is required to move in alignment with the center of the sheet width.
(6) In a conventional ink jet recording apparatus, movement of a wiping blade is accomplished only by a cam and a gear provided in a recovery device.
However, the demand for the reduction of the size requires reduction of the number of parts and simplification thereof. However, for the purpose of improving print quality, the wiping means itself becomes complicated, and therefore, the number of parts tends to increase.
(7) In a conventional apparatus, an adjusting member for the lead screw and a spring are separate members. Therefore, if the lead screw is adjusted, the spring member is also required to be adjusted. Accordingly, the number of parts increases.
(8) In a conventional apparatus, projection members of a slide gear are symmetrically arranged, and therefore, there are plural engageable positions, and therefore, the assembling operation must be carried out with great care.
(9) In the head cartridge in which the ink ejection outlets are spaced apart from electric contacts, the size of the head cartridge is relatively large in order to provide the sufficient distance. In a head cartridge in which a cover is provided in the vicinity of electric contacts, the size of the head cartridge increases by the provision of the cover. In addition, since there is a limit to the arrangements of the ink ejection outlets and the electric contacts, design freedom decreases. In addition, the ink may enter the electric contact portion causing an unintentional short circuit with the possible result of damage of the recording head or the main assembly of the recording apparatus.
(10) In a wiping mechanism of a recovery device in a conventional ink jet recording apparatus, as shown in FIG. 46, a blade arm 161 supporting a blade 162 rotates about a pivot 161a to wipe the ejection side surface 160b of the recording head portion 160a of a cartridge 160. In order to completely remove the ink from the ejection side surface 160b, an entering amount a of the blade 162 relative to the ejection side surface 160b is within a certain range. However, in the conventional arrangement, the blade 162 moves arcuately and therefore, the entering amount a of the blade 162 to the ejection side surface 160b of the head is not constant. In order to completely remove the ink from the ejection side surface 160b, the positional relation between the ejection side surface 160b and the blade 162 has to be accurately controlled. This means that the required tolerance of the parts and the accuracy of assembling, is very high.
(11) In the conventional apparatus, the ink on the blade is removed by contacting an absorbing material to the blade with light pressure, and the blade is placed at the position. However, if the blade is kept contacted by the absorbing material for a long time in the conventional apparatus, the blade becomes deformed, so that the blade no longer functions to wipe out the ink.
Accordingly, it is a principal object of the present invention to provide an ink jet recording apparatus having a small size.
It is another object of the present invention to provide a small printer built in an information processing apparatus.
These and other objects, features and advantages of the present invention will become more apparent upon a consideration of the following description of the preferred embodiments of the present invention taken in conjunction with the accompanying drawings.